Are volume-dependent parameters in positron emission tomography predictive of postoperative recurrence after resection in patients with thymic carcinoma?

This study aimed to investigate the association between the volume-dependent parameters in 18F-fluorodeoxyglucose-positron emission tomography (18F-FDG PET/CT) and a recurrence of thymic carcinoma. A retrospective chart review was performed based on our multi-institutional database to identify patients undergoing PET prior to resection of thymic carcinoma or neuroendocrine carcinoma between 1991 and 2018. The PET parameters (metabolic tumor volume and total lesion glycolysis) were evaluated retrospectively. The relevant factors were extracted and a survival analysis was performed using the Kaplan-Meier method. Sixteen patients were thus deemed to be eligible for analysis. The median follow-up period following resection was 2.65 years (range: 0.96-0.68 years). The recurrence-free survival was significantly longer in patients with a metabolic tumor volume < = 22.755 cm3 and with total lesion glycolysis < = 105.4006 g/mL (p = 0.001 and 0.001, respectively, by a log-rank test). The metabolic tumor volume and total lesion glycolysis may, therefore, be predictive of the postoperative recurrence of thymic carcinoma.

The treatment and survival of patients with postoperative recurrent thymic carcinoma and neuroendocrine carcinoma: a multicenter retrospective study.

PURPOSE: There are few data available on the outcomes of postoperative recurrent thymic carcinoma (TC) and thymic neuroendocrine carcinoma (TNEC). The aim of this study is to evaluate the treatment and survival in patients with recurrent TC and TNEC after undergoing surgical resection. METHODS: A retrospective chart review was performed using our multicenter database to identify patients with a postoperative recurrence of TC and TNEC from 1995 to 2018. The clinicopathological factors were reviewed and the survival outcomes were analyzed. RESULTS: Sixty patients were identified among 152 patients who underwent resection of TC and TNEC. The median follow-up period from the first recurrence was 14.8 months (range 0-144). The 5-year post-recurrence survival was 23% for the whole cohort. According to a univariable analysis, advanced stage [hazard ratio (HR) 2.81, 95% confidence interval (CI) 1.09-9.54], interval between primary surgery and recurrence (HR 0.97, 95% CI 0.95-0.99), any treatment for recurrence (HR: 0.27, 95% CI 0.13-0.58) and chemotherapy for recurrence (HR: 0.46, 95% CI 0.22-0.95) were significant factors related to post-recurrence survival. CONCLUSIONS: Chemotherapy rather than surgery appears to be the mainstay treatment for managing patients with postoperative recurrent TC and TNEC and it may also be considered in multidisciplinary management. Further studies with a larger sample size are required to confirm our findings.

Lymph node dissection in thymic carcinomas and neuroendocrine carcinomas.

OBJECTIVES: Although lymph node (LN) metastases are not uncommon in thymic carcinomas, preoperative LN evaluation, intraoperative lymph node dissection (LND) and postoperative outcomes remain unknown. The aim of this study was to elucidate the characteristics of and outcomes in patients with thymic carcinomas and thymic neuroendocrine carcinomas undergoing LND. METHODS: A retrospective chart review was performed using our multi-institutional database to identify patients who underwent resection and LND for thymic carcinoma or thymic neuroendocrine carcinoma between 1991 and 2018. An enlarged mediastinal LN was defined as having a short-axis diameter >1 cm. We assessed survival outcomes using the Kaplan-Meier analysis. RESULTS: N1-level LND was performed in 41 patients (54.6%), N2-level LND in 14 patients (18.7%) and both-level LND in 16 patients (21.3%). Pathological LN metastasis was detected in 20 patients (26.7%) among the 75 patients undergoing LND. There was a significant difference in the number of LN stations (P = 0.015) and metastasis factor (P = 0.0042) between pathologically LN-positive and pathologically LN-negative patients. The sensitivity of enlarged LNs on preoperative computed tomography was 18.2%. There was a tendency towards worse overall survival of pathologically N2-positive patients, although the difference was not statistically significant (P = 0.15). CONCLUSIONS: Preoperative CT appears to play a limited role in detecting pathological LN metastases. Our findings suggest that the significance of N1- and N2-level LND should be evaluated in prospective studies to optimize the postoperative management of patients with thymic carcinomas and neuroendocrine carcinomas.

Survival outcomes of patients with high-grade and poorly differentiated thymic neuroendocrine carcinoma.

High-grade and poorly differentiated thymic neuroendocrine carcinoma is the rarest entity in thymic epithelial tumours. The aim of this study is to report survival data in a multi-institutional database in comparison to data in the literature. Retrospective chart review was performed on the basis of our multi-institutional database to identify patients undergoing the resection of poorly differentiated thymic neuroendocrine carcinoma between 1991 and 2018. Relevant factors were extracted, and survival analysis was performed using the Kaplan-Meier method. Twenty-one patients were identified. Five-year overall survival and recurrence-free survival were 64.6% and 51.8%, respectively. Twelve (57.1%) patients had recurrences. Due to the scarcity of data reported in the literature, our data may be used as a standard in high-grade and poorly differentiated thymic neuroendocrine carcinoma.

Prognostic factors after complete resection of pN2 non-small cell lung cancer.

OBJECTIVES: This retrospective, multicenter study aimed to determine prognostic factors of completely resected pathologic N2 stage IIIA non-small cell cancer (NSCLC). METHODS: From 25 participating hospitals, 496 patients (325 men and 171 women; median age, 65 years) who underwent complete resection without preoperative treatment for pT1-3 N2 M0, stage IIIA NSCLC between 2000 and 2004 were enrolled. Lobectomy/bilobectomy was performed in 462 patients and pneumonectomy in 34. Some kind of adjuvant chemotherapy was administered to 296 patients. Survivals were calculated using the Kaplan-Meier method, and prognostic factors were determined using the Cox proportional hazards model. RESULTS: Five-year overall survival (OS) and disease-free survival (DFS) were 44.8% and 24.2%, respectively. pT classification (hazard ratio (HR), pT1/pT2/pT3 = 1/1.32/2.03), single or multiple N2 metastases (HR, single/multiple = 1/1.36), and skip or nonskip N2 metastasis (HR, skip/nonskip = 1/1.30) were found to be independent prognostic factors for DFS. Sex (HR, female/male = 1/1.36), performance status (HR, PS-0/PS-1 = 1/1.37), tumor diameter (HR, 1.12 per 1-cm increase), pT-factor (HR, pT1/pT2/pT3 = 1/1.37/2.22), and extent of N2 metastasis (HR, localized/extended = 1/1.39) were shown to be independent prognostic factors for OS. CONCLUSIONS: We found that pT classification was a significant prognostic indicator for OS and DFS whereas tumor diameter, performance status, and sex were ones for OS. Single N2 metastasis and skip N2 metastasis were demonstrated as favorable prognostic factors for DFS, limited N2 metastasis was one for OS, and these should be considered as stratification factors for trial on adjuvant therapy.

Diagnostic usefulness of an amino acid tracer, α-[N-methyl-(11)C]-methylaminoisobutyric acid ( (11)C-MeAIB), in the PET diagnosis of chest malignancies.

OBJECTIVES: Although positron emission tomography (PET) using [(18)F]-fluoro-2-deoxy-D-glucose ((18)F-FDG) is established as one of the first-choice imaging modalities in the diagnosis of chest malignancies, there are several problems to solve in clinical practice, such as false positive uptake in inflammatory diseases. The aim of this study was to evaluate the clinical usefulness of an amino acid tracer, α-[N-methyl-(11)C]-methylaminoisobutyric acid ((11)C-MeAIB), in the diagnosis of chest malignancies, in combination with (18)F-FDG. SETTING: Fifty-nine cases (57 patients, 66 ± 12 years old) who consulted to our institution for the wish to receive differential diagnosis of chest diseases were included. Purpose of the studies were as follows: differential diagnosis of newly developed lung nodules, n = 22; newly developed mediastinal lesions, n = 20; and both, n = 17 (including lung cancer: n = 19, lymphoma: n = 1, other cancers: n = 2, sarcoidosis: n = 15, non-specific inflammation: n = 18, other inflammatory: n = 4, respectively). Whole-body static PET or PET/CT scan was performed 20 and 50 min after the IV injection of (11)C-MeAIB and (18)F-FDG, respectively. RESULTS: (11)C-MeAIB uptake of malignant and benign lesions was statistically different both in pulmonary nodules (p < 0.005) and in mediastinal lesions (p < 0.0005). In visual differential diagnosis, (11)C-MeAIB showed higher results (specificity: 73 %, accuracy: 81 %), compared to those in (18)F-FDG (60, 73 %, respectively). In cases of sarcoidosis, (11)C-MeAIB showed higher specificity (80 %) with lower uptake (1.8 ± 0.7) in contrast to the lower specificity (60 %) with higher uptake of (18)F-FDG (7.3 ± 4.5). CONCLUSIONS: (11)C-MeAIB PET/CT was useful in the differential diagnosis of pulmonary and mediastinal mass lesions found on CT. (11)C-MeAIB PET or PET/CT showed higher specificity than that of (18)F-FDG PET/CT in differentiating between benign and malignant disease. Our data suggest that the combination of (18)F-FDG and (11)C-MeAIB may improve the evaluation of chest lesions, when CT and (18)F-FDG PET/CT are equivocal.